Beverage package

ABSTRACT

The present invention relates to a novel type of beverage infusion package which allows the infusion product contained inside or supported thereon to be identified by a printed logo or brand. In particular the infusion product is coffee or tea. The beverage infusion package is formed of paper or other non-woven material used for beverage packages and can be used in a whole range of coffee and tea beverage filtration packaging such as tea bags, hard pods, soft pods, coffee pouches and systems in which a container incorporates the paper with the tea, coffee or other infusion beverage. The beverage package may be a “one-cup” style bag containing sufficient infusion material, eg tea, for a single serving or may be a “multi-brew” style bag containing sufficient material for more than one serving. The present invention enables printing to be applied to the package without any deleterious effects to the integrity of the package and without the risk of introducing hazardous materials into the product.

The present invention relates to a novel type of beverage infusion package which allows the infusion product contained inside or supported thereon to be identified by a printed logo or brand. In particular the infusion product is coffee or tea. The beverage infusion package is formed of paper or other non-woven material used for beverage packages and can be used in a whole range of coffee and tea beverage filtration packaging such as tea bags, hard pods, soft pods, coffee pouches and systems in which a container incorporates the paper with the tea, coffee or other infusion beverage. The beverage package may be a “one-cup” style bag containing sufficient infusion material, eg tea, for a single serving or may be a “multi-brew” style bag containing sufficient material for more than one serving. The present invention enables printing to be applied to the package without any deleterious effects to the integrity of the package and without the risk of introducing hazardous materials into the product.

Beverage infusion packages comprise a beverage precursor material (e.g. tea leaves or ground coffee) enclosed within a bag, pouch, sachet or the like (all conveniently referred to herein as a bag) of a paper usually having a basis weight in the range 9 to 40 g/m². The paper or other non-woven material is frequently referred to as “tissue” or “tea bag tissue” and is typically formed by a conventional wet-laying technique in which at least one layer is in an aqueous suspension of paper forming fibres is laid onto a traveling, water pervious paper-forming screen with water then being drained through the screen to produce the paper. The paper may be of the “heat seal” or “non-heat” type.

The second or further layers may be added using the same methods or by laying a layer using other paper making techniques such as melt blown techniques.

Paper webs suitable for forming beverage packages, such as tea bags, and including polypropylene scrims are made by dry laying techniques known in the art. Such materials can also be printed in accordance with the invention.

The present invention is also concerned with the production of both heat-seal and non-heat seal beverage infusion packages based on conventional papers used in the manufacture of tea bags and coffee infusion packages, or on papers containing a high percentage of wood pulp described herein which have their own particular advantages due to the high wood pulp content. In either case, the papers have been treated to impart the required properties but the papers may optionally also contain an antioxidant or other additives as desired in accordance with the invention. The packages of the present invention consequently enjoy a good shelf life whilst providing convenience to the consumer.

The tissue may be of the heat seal type which incorporates thermoplastic fibres and from which the beverage infusion bag is produced by heat sealing two layers of the tissue together. Alternatively the tissue may be of the non-heat seal type from which the closure seams (s) of the beverage infusion bag is/are produced by a mechanical, eg crimping, action without heat sealing.

Heat seal paper comprises a web of one or more layers. A single layer heat sealed paper contains cellulosic and thermoplastic fibres. In the case of webs having two or more layers, one layer may contain cellulosic fibres and the other layer may incorporate thermoplastic fibres which are to form the basis of the heat seal. In another arrangement the inner (structural) layer comprises both cellulosic fibres and thermoplastic fibres. The entrained thermoplastic fibres provide a stronger heat seal between two webs of the tissue paper because the thermoplastic forming the heat seal is an integral part of the structural layer. The second or third layer which forms the outer layer is an insulating layer of material whose primary function is to protect the rollers of the processing machinery from the thermoplastic-containing structural layer during processing.

Non-heat seal paper usually comprises a web of material which is a single layer of cellulosic fibres. However, such webs may be formed from two or more layers. A package is formed by folding the paper and forming a mechanical closure seam to seal the package.

It is often required that the tissue be produced with a pattern. Various examples of patterns are used, e.g. the initials and/or logo of the manufacturer of the beverage infusion packages. Alternatively the pattern may comprise a repeat of small circular or diamond-shaped “dots” that are intended to give the impression of perforations in the tissue.

Various methods of producing patterns in tissue are known.

One such technique is fluid jet-patterning. In this technique, the pattern is formed using fluid jets (usually water) directed at the web whilst it is still on the paper forming screen during the process of manufacture by wet-laying. In more detail, a cylindrical patterning screen rotating about a horizontal axis is provided above the paper forming screen and its wall is pierced by apertures that define the pattern to be produced. Within the cylindrical patterning screen is a source of fluid jet pressure (e.g. a water supply) which is directed radially outwardly so as to traverse the apertures in the patterning screen and issue as jets which form the pattern in the web.

This technique does however have the disadvantage that there can be a reduction in the mechanical strength of the web as compared to that obtainable without fluid jet patterning due to disruption of the fibre structure of the web. In extreme cases the web may be ripped. Additionally the sifting characteristics of the web may be poor allowing fines of beverage precursor material to be lost from the final infusion bag.

Moreover water jet patterning requires large amounts of water over and above those used for forming the wet laid suspension in the paper forming screen.

In the case of a pattern which is comprised of repeating dots (to give the impression of perforations) this may be produced by protrubences (so-called “knuckles”) projecting from the paper-forming screen of a wet laid manufacturing process. The fibre density (I.e. the number of fibres per unit area) in the region of the paper formed on the knuckle is less than in the other regions thereby giving the impression of a pattern. This technique does however suffer the disadvantage that the localized open area and reduction in fibre density created by the wire knuckles causes (i) an area of mechanical weakness in the paper web at that point; (ii) poor sifting characteristics; and (iii) poor and variable pattern definition.

Furthermore the use of “knuckles” limits the morphology of fibres that may be used due to the sheet release characteristics of the wire design. A further disadvantage is that there is only limited scope for “personalising” papers (e.g. with a particular logo or other trade mark).

British Patent No 2286159 discloses a method of embossing tissue paper used in the production of filtration bags used for infusion beverage products such as tea bags. However, this document also discloses that the process of patterning or providing discreet logo images in the tissue paper during production can disrupt the fibre distribution and create regions of high and low fibre density. Although this is desirable in that, when viewed against the darker content of the bag, a pattern is revealed by optical contrast, there is the problem that subsequent regions of low fibre density result in significant reductions in paper strength. There is a further problem that the loss of ingredient particles may occur due to the existence of voids within these contrast regions. An alternative method used in the prior art involves hot calendering to provide the combined action of heat and pressure on tissue paper in order to compact fibres and reduce the thickness. However, the same problems remain because the action of heating and compacting the paper necessarily disturbs the fibre web and may lead to a loss in structural integrity.

It is the aim of the present invention to provide a paper web which can be printed and then formed into packaging material which is suitable for packing individual portions of an infusion beverage. The invention seeks to avoid the need for unnecessary additives being required in a printed product. A further aim is thus to provide a printed package which is safe to use and which does not require the use of additives not normally present in such packages absent printed regions and hence which does not require further regulatory approval by food agencies. Ideally, the package should be ready for immediate use and yet also be able to be stored for an extended period of time. It is another aim of the invention to provide a beverage package which comprises the paper web of the invention together with an infusion product. It is a further aim that the beverage package contains an individual portion of the beverage such as coffee or tea for single use without the need for unwrapping the package. It is a further aim that the packaging material used to make the beverage package, and the beverage package itself, be biodegradable to at least some extent so that once the package has been used and disposed of by the consumer it will not have a deleterious effect on the waste stream and on the environment in general. It is also an aim that the tissue paper acts as a filter.

More particularly, it is intended that the printed paper should be capable of use in both heat seal and non-heat seal packages. It is a further aim that the paper should have good wet and dry strength and be resistant to bursting so that the product is retained securely. It is thus an aim of the present invention to provide a beverage infusion package which retains its structural integrity. It is also desired that the resulting package has a good crimp strength once sealed to form a closed package. It is thus an aim of the present invention to provide a paper which can be used in the production of a non-heat sealed package eg a coffee bag having a high crimp strength and a resistance to failure. It is a further object of the invention to provide a package and a paper web for the production of a package which is easy to process and economical to product. It is a further aim to produce a relatively light weight paper suitable for packaging or retaining coffee. Another aim is to produce a package formed from a printed paper web which is acceptable for use in food products. It is also an aim to provide a process for preparing the printed paper web used in the package.

The present invention satisfies some or all of the above objects.

According to one aspect of the present invention, there is provided a paper web of porous, fibrous, material suitable for producing a beverage infusion package wherein the paper web has a grammage of 9 to 40 gm⁻² and wherein the paper web includes a printed region bearing printed matter in which the printing ink is derived from an infusion beverage.

In another aspect of the present invention there is provided a beverage infusion package formed of porous, fibrous, material and having a grammage of from 9 to 40 gm⁻², wherein the package contains an infusion beverage and wherein the paper web includes a printed region bearing printed matter in which the printing ink is derived from an infusion beverage.

The material forming the paper web is preferably of cellulosic origin.

The printed infusion beverage package comprises a sealed body having at least one internal compartment, said internal compartment containing an infusion beverage, wherein said sealed body is constructed of a web of porous, fibrous, material which allows the flow of fluid through the sealed body to extract material from the internal compartment. The internal compartment usually contains from 2 to 10 g of the infusion beverage but may contain up to 200 g in exceptional circumstances.

In an embodiment, the majority of particle size of the beverage is from 0.05 to 5.0 mm and is preferably in the range 0.20 to 0.50 mm. In this context, the majority means 75% or more, and ideally 90% or more, of the particles. The web may also contain embossing so that one or both sides of the package contain, separately, one or more embossed markings in addition to the printing.

In an embodiment, the printing ink is derived from the same beverage as the infusion beverage contained within the beverage package. Preferably the ink is of tea origin.

In a further embodiment, the printed region is from 1 to 70% of the surface area of the beverage package. More preferably the printed region is 2 to 30% of the surface area. The printing may appear on one or both external sides of the paper web forming the beverage package.

The ink is made from an extract of an infusion beverage. Ideally, the extract is an aqueous extract of the infusion beverage. However, a non-water soluble extract could be used. Preferably the extract is derived from tea. The extract is derived only from the beverage and contains no additives at that stage. In order to render it suitable for printing on to the paper web used to produce the beverage package a viscosity modifier is added to the extract. The viscosity modifier may be any suitable viscosity modifier approved for use in food. The viscosity modifier is added to adjust the specific gravity of the extract to give a suitable viscosity for printing. The viscosity modifier is added in an amount of from 0.1% to 20.0% by weight of the solids content and more preferably in the range of 0.5% to 5%, and most preferably in the range 1.0% to 2.0%. The essential function of the modifier is to enable printing without the print head gumming up or without the ink being too mobile leading to running or smudging. Particularly preferred viscosity modifiers include a carboxy methyl cellulose (CMC), xanthan gum, guar gum, locust bean gum and starch.

The beverage extract is obtained as a solid and is dissolved in water to form a solution of from 10 to 80% by weight of the extract present in solution and preferably in the range of 45 to 65% by weight. More preferably, the beverage extract is present in solution in an amount of 45 to 55% by weight.

The convenience of the arrangement of the present invention provides a number of significant advantages. Firstly, there is a benefit because processing using techniques such as a fluid-jet patterning are not required. Secondly, the use of natural infusion-derived materials to produce the ink used in the printing process means that no unnecessary additives are introduced. This has both an environmental benefit and a health benefit in that valuable resources are not being consumed and subsequently entering the waste stream and that unnatural ink-based chemicals are not introduced into the beverage. This is a significant benefit in marketing the produce to the consumer.

There is also the advantage that because the beverage packages of the present invention do not contain a large number of unnecessary additives they are thus simpler and more economical to manufacture than conventional inks.

Any conventional “tissue-type” paper which is used as a base material for preparing infusion packages may be used according to the present invention. Thus the paper web contains cellulosic material and can be described as porous fibrous cellulosic material. This includes biodegradable papers of known type. The invention also thus includes the use of papers of the type described in our earlier international patent no WO97/04956 and the contents of that disclosure are specifically incorporated herein.

Each layer of the web may be independently produced from fibres (e.g. hardwood fibres) which are shorter and finer than fibres such as vegetable fibres. Alternatively, it is possible for the web to comprise fibres which are coarser than vegetable fibres and the like and to be used in an amount such as to provide a highly tortuous path along which a particle would need to pass to traverse the web.

The hardwood fibres preferably have a length of 0.4 mm to 2.5 mm and may for example have a mean length of about 0.8 mm. The fibre width may be 10 to 25 microns with a mean of about 14 microns. Hardwood fibres are finer and shorter than softwood fibres. Examples of hardwood fibres which may be used include birch, beech and eucalypt. If desired, the second layer may comprise of Softwood, Sisal and/or Jute or man made fibres as part of the fibre components of the layer.

Vegetable fibres generally have a length of 0.8 mm to 9 mm and may for example have a mean length of about 4.3 mm. A suitable vegetable fibre is Manila (Abaca).

If desired, the web may comprise Sisal and/or Jute as part of the vegetable fibre component of the layer. It may also be possible to produce a similar material with man made fibres.

If desired, a proportion of the vegetable fibres of the web may be replaced by softwood fibres. Preferably the amount of softwood fibres does not exceed 75% by weight of the web. Softwood fibres are long, flat ribbon-like fibres which are readily distinguished by a person skilled in the art from vegetable fibres and hardwood fibres. The softwood fibres may have a length of 0.8 mm to 5 mm and a width of 12 to 60 microns. Typical means of these values are 3.8 mm and 29 microns respectively. The softwood fibres may for example be obtained from spruce, pine, cedar, western hemlock, fir or redwood.

It is preferred that the web material of the invention has a thickness in the range of 30-100 m more typically in the region of the 40-60 m.

It should be appreciated that the invention covers papers comprising one, two, three or more layers which may be the same or different.

Conventionally, both the heat seal paper and the non-heat seal paper are produced from cellulosic fibres produced from mixtures of well known paper-making fibres. As described above, suitable fibres for producing a paper web may thus include both wood and non-wood materials such as manila, hemp, sisal, jute, bleached and un-bleached softwood and hardwood species, and sometimes compatible synthetic fibres such as viscose rayon and spun bonded rayon are also included. Synthetic fibres such as polyester and polypropylene can also be incorporated with the wood pulp.

Paper suitable for the production of infusion packages may contain up to 100% wood, and up to 100% long fibre, or lesser proportions as required. Wood pulp, typically about 30 to 80% by weight of the cellulosic material, is added to modify the web properties.

The paper material is generally treated with classic wet and dry strength chemical enhancing products such as carboxymethyl cellulose (CMC), polyamide epichlorohydrin, and melamine formaldehyde.

Conventional materials used in existing paper for the production of tea include abaca, manila, sisal and jute in conjunction with wood pulp.

We have also found in one embodiment of the invention that it is possible to incorporate relatively high proportions (more than 65%) of wood pulp into paper whilst maintaining or improving the wet strength of the paper. The paper can thus be used to produce beverage infusion packages such as coffee which have good wet and dry strength. We have also found in this case that it is not always necessary to include dry strength additives, in particular carboxymethyl cellulose (CMC) in the paper. The paper of this embodiment invention has good dry strength in its own right without CMC being added.

In an embodiment, the paper web has a grammage of 9 to 40 gm⁻² and incorporates one or more antioxidants in a total amount of from 0.01% to 50% by weight of the paper web.

Thus we have found that by incorporating an antioxidant into tissue paper or providing a covering of the antioxidant on the tissue paper enables a package to be produced in accordance with the invention which provides an extended shelf life for the product contained within.

In a further embodiment, the amount of antioxidant in the paper is from 0.5% to 10% by weight of the paper web. This leads to excellent storage properties and shelf life for the product to be packaged whilst avoiding the need for a high loading of additive.

In another embodiment, the antioxidant is provided on one or both surfaces of the paper web. Preferably, the antioxidant is provided by spray coating, surface coating or printing. In another embodiment, the antioxidant is incorporated into the body of the paper web. Equally, the paper web may have both a surface coating of the antioxidant and contain antioxidant in the body of the web.

In another embodiment the antioxidant is one or more selected from the group comprising: alkylphenols, hydroxy phenolpropionates, hydroxybenzyl compounds, alkylidene bisphenols, secondary aromatic amines, thio bisphenols, aminophenols, thioethers, phosphites and phosphonites, sterically-hindered amines, carotenoids, polyphenols, tea flavanoids or any compounds identified as acceptable in FDA REGULATIONS 21CFR Section 178.2010 or 178.2550. Thus any combination of the above can be used as the antioxidant. Phenol-containing compounds are particularly preferred.

It is essential that the antioxidant is suitable for use in food products. Any antioxidant which has been approved for use in conjunction with food or which is capable of being used with food in accordance with regulatory requirements may be used in the paper of the present invention.

Whilst the paper web generally has a grammage of 9 to 40 gm⁻² it is more typically in the range of 9 to 25 gm⁻². It is preferred that the material has a grammage of from 9 to 25 gm⁻² from the point of view of producing a package which has good dry and wet strength and yet which allows effective infusion of water into the package.

Conventional additives such as wet and dry strength agents, sizing agents and fillers may be incorporated in the paper as required to give the paper desired properties. Thus wet strength agents, preferably in an amount of not more than 10% by weight, such as melamine formaldehyde and polyamide epichlorohydrin can be added.

The manufacturing process for the paper which forms the basis for the paper of the present invention is conventional and thus will not be described here in detail. The tissue paper is obtained by conventional processing means such as wet laid tissue paper which is produced by a conventional inclined wire machine used for making long-fibre tissue paper, but could be made under the right conditions on a flat wire machine. Briefly, the process involves dispersion of the fibrous material in water followed by mechanical treatment of the fibres (refining) in order to enhance the cross bonding between fibres. The next stage involves blending the fibrous components together and the addition of any necessary dry or wet strength chemicals. The liquid dispersion of fibre (stock) is then cleaned in hydra-cyclones to remove dense contrary material. The dilute stock is then screened. The paper web is formed by metering the very dilute stock onto an endless mesh (wire). The water is drained away and the wet web is carried forward to the drier part of the paper-making machine. The resulting wet paper web is dried by hot air and contact with steam heated cylinders or other drying methods and optional surface treatment of the paper surface is then performed. It is at this stage that functional chemicals such as sizing agents may be added. Further drying, including curing of wet strength resins and thermal bonding of any thermoplastic component is then effected. The final stages of the process involve moisture correction with water or steam spray, calendaring to control the thickness or smooth the paper surface, and recling the continuous web onto a roll. The antioxidant or mixture of antioxidants can be added or applied to the paper at various different stages of the production process. Suitable solvents for applying the antioxidant include both aqueous and non-aqueous solvents. Ethanol or water is particularly preferred. Other known processes may also be used.

The print may then be applied to the printed region of the paper by conventional screen printing techniques.

The manufacture of beverage packages such as tea bags from the paper web of this invention is achieved in the case of non-heat sealed paper by folding, crimping and stapling as described in our earlier patent No WO01/41610. In the case of heat sealable papers, two webs of paper are placed together with their thermally active surfaces facing one another and then compressed between heated rollers. Ultrasonic or other suitable methods of sealing thermoplastic surfaces may also be used.

The beverage packages of the present invention have the further advantage that printing may be applied to the package either for the purpose of decoration or for the purpose of identification despite the relatively high porosity of the paper. The printed beverage packages according to one embodiment of the present invention are specially designed so that the ink remains on the package until the package is exposed to hot water.

The provision of a printed package according to the invention containing such identifying marks has a number of advantages. Firstly, it may act as a guarantee of quality and origin so that the user may identify the manufacturer and nature of the beverage. Secondly, it may act as an anti-counterfeiting measure to prevent low quality imitations of a well known product being mistaken for the genuine product. Thirdly, there is the significant advantage that it is possible to provide warning indicia on the package itself. Such indicia may be used, for example, to warn the user, for example, of the “sell-by” date or in the case in which the contents are coffee that the contents contain caffeine or advise users that the material is decaffeinated (and therefore safe for users with an adverse reaction to caffeine).

The principle of the present invention may be applied to both closed beverage packages (for example, tea bags and coffee pods etc.) in which an infusion beverage is contained within a sealed body having at least one internal compartment, or to open filtration packaging (for example, coffee filter papers and pouches etc.) in which the beverage is not sealed within an internal compartment and the paper web simply provides a filtration barrier to the passage of the beverage during the infusion/extraction process with hot water.

EXAMPLE 1

A printing ink was made from tea extract. 100% natural tea powder was made up into solution in water and CMC added as the viscosity modifier. The amount of tea and CMC added was calculated to produce a solution containing 49% tea, 1% CMC and 50% water. The solution was then used in the ink reservoir of a screen printer to print tissue papers of between 9 and 25 gm⁻². 

1. A paper web of porous, fibrous, material suitable for producing a beverage infusion package wherein the paper web has a grammage of 9 to 40 gm⁻² and wherein the paper web includes a printed region bearing printed matter having a printing ink derived from an infusion beverage.
 2. A paper web according to claim 1 which has been formed into a beverage infusion package, wherein the package comprises a sealed body having at least one internal compartment, said internal compartment containing an infusion beverage, and wherein the package includes a printed region bearing printed matter in which the printing ink is derived from an infusion beverage.
 3. A paper web according to claim 2, wherein one or both sides of the package contain, separately, one or more embossed markings in addition to the printed matter.
 4. A paper web according to claim 1, wherein the material forming the paper web is of cellulosic origin.
 5. A paper web according to claim 2, wherein the internal compartment contains from 2 to 10 g of the infusion beverage.
 6. A paper web according to claim 1, wherein the ink is an aqueous extract of the infusion beverage and the solid extract is dissolved in water to form a solution of from 10 to 80% by weight of the extract.
 7. A paper web according to claim 2, wherein the printing ink is derived from the same beverage as the infusion beverage to be contained within the beverage package.
 8. A paper web as claimed in claim 7, wherein the ink is of tea origin.
 9. A paper web according to claim 1, wherein the ink includes a viscosity modifier.
 10. A paper web according to claim 9, wherein the viscosity modifier is added in an amount of from 0.1% to 20.0% by weight of the solids content.
 11. A paper web according to claim 9, wherein the viscosity modifier is one or more selected from the group consisting of: carboxy methyl cellulose (CMC), xanthan gum, guar gum, locust bean gum and starch.
 12. A paper web according to claim 2, wherein the printed region is from 1 to 70% of the external surface area of the beverage package.
 13. A paper web as claimed in claim 7, wherein the ink is of coffee origin.
 14. A paper web according to claim 2, wherein the printing ink is derived from a different beverage as the infusion beverage contained with the beverage package.
 15. A paper web of porous, fibrous, material suitable for producing a beverage infusion package wherein the paper web has a grammage of 9 to 40 gm⁻² and wherein the paper web includes a printed region bearing printed matter, in which a printing ink is derived from an infusion beverage, and wherein the package comprises a sealed body having at least one internal compartment, said internal compartment containing an infusion beverage, wherein the printing ink is derived from the same beverage as the infusion beverage to be contained within the beverage package, and the material forming the paper web is of cellulosic origin.
 16. A paper web according to claim 15, wherein the infusion beverage and the printing ink are of tea origin.
 17. A method of preparing a beverage package comprising printing a paper web of porous, fibrous material having a grammage of 9 to 40 gm⁻² with a printing ink derived from an infusion beverage.
 18. A method according to claim 17, further comprising forming at least one internal compartment containing an infusion beverage.
 19. A method according to claim 18, wherein the step of printing the web is prior to the step of forming the internal compartment.
 20. A method according to claim 17, wherein the infusion beverage is tea. 